KR102577808B1 - Wastewater treatment method using mixed treatment of dyeing wastewater and heterogeneous wastewater - Google Patents

Abstract

The present invention relates to a wastewater treatment method using mixed treatment of dyeing wastewater and wastewater from other industries, and more specifically, to a wastewater treatment method using mixed treatment of dyeing wastewater and wastewater from other industries, wherein dyeing wastewater homogenized with wastewater from other industries is mixed and stirred in a neutralization tank, and a coagulant is added to mixed treated water reacted to pH 9 to 10 by injecting FeSO_4 and Ca(OH)_2 to cause coagulation and precipitation, thereby most efficiently and quickly removing non-degradable contaminants contained in dyeing wastewater.

Description

Wastewater treatment method using mixed treatment of dyeing wastewater and heterogeneous wastewater}

The present invention relates to a wastewater treatment method using mixed treatment of dyeing wastewater and wastewater from a different industry. More specifically, the dyeing wastewater homogenized with wastewater from a different industry is mixed in a neutralization tank, stirred, and then FeSO ₄ and Ca(OH) Dyeing _wastewater and wastewater from other industries can most efficiently and quickly remove non-decomposable contaminants contained in dyeing wastewater by adding coagulant to coagulate and precipitate the mixed treated water that has been injected and reacted to pH 9 ~ 10. It relates to a wastewater treatment method using mixed treatment.

Dyeing wastewater contains many non-degradable contaminants that are difficult to biologically treat. Therefore, after performing primary treatment to remove these non-degradable contaminants in advance or breaking the long molecular chains of organic matter so that microorganisms can decompose and absorb them, the remaining organic matter is secondarily treated using a biological treatment method using microorganisms. The primary treatment technology for dyeing wastewater includes various methods such as ozone oxidation, electrolysis, microwave irradiation, plasma decomposition, and photocatalytic oxidation.

Although these methods require a lot of energy, their treatment efficiency varies greatly depending on the properties of the dyeing wastewater. Although they are valuable for treating dyeing wastewater containing a single substance, they are less efficient in treating dyeing wastewater composed of complex substances. Therefore, in most dyeing companies, the dyeing method used varies depending on the dyeing method or type of fabric. As most of the dyeing wastewater discharged from dyeing companies is rarely single dyeing wastewater, treatment methods such as electrolysis are the main treatment methods. No, it is widely used as an auxiliary processing method in some areas.

Another method is to continuously repeat several stages of biological treatment, such as aerobic treatment and anaerobic treatment, or repeat the same method several times, such as aerobic treatment and aerobic treatment, to decompose non-degradable pollutants and organic matter in dyeing wastewater into microorganisms and purify them. There are other methods, but these methods can be said to be the best alternative as an eco-friendly treatment method using natural microorganisms. However, these methods have the problem that the decomposition rate for non-decomposable organic substances is slow, so the site area required for treatment is large, and color removal is difficult.

Meanwhile, oxidizing substances such as sulfuric acid or hydrochloric acid are added to the incoming dyeing wastewater to strongly acidify the pH to about 3 to 3.5, and hydrogen peroxide ^and iron salt are added to reduce the color of the dyeing wastewater. In an acidic atmosphere, Fe eluted from iron salt reacts with non-decomposable contaminants and precipitates into iron chloride oxide sludge, a non-decomposable contaminant. The precipitated iron chloride oxide sludge is coagulated and separated into solid and liquid in a solid-liquid separator, and the solid is dehydrated in a dehydrator. The Fenton oxidation method for dyeing wastewater is a treatment method in which organic matter remaining in the primary treatment water is decomposed and removed using microorganisms while the primary treatment water from which non-biodegradable substances have been removed passes through an aeration tank and a sedimentation tank. This is described in Korean Patent Publication No. 10-1996-0031353 (Patent Registration No. 10-0145467).

The Fenton oxidation method for dyeing wastewater has good treatment efficiency, but it requires the addition of hydrogen peroxide to remove color, sulfuric acid added to strongly acidify the entire dyeing wastewater under Fenton oxidation conditions, and caustic acid to neutralize the primary treatment water again after the Fenton oxidation treatment. A large amount of acid and alkaline chemicals such as soda are injected, resulting in high chemical costs. In particular, there is a problem in that all the iron salts and acid and alkaline chemicals added are converted into sludge, resulting in an increase in the amount of dehydrated cake.

The purpose of the present invention is to mix and stir dyeing wastewater homogenized with wastewater from different industries in a neutralization tank, then inject FeSO ₄ and Ca(OH) ₂ and add a coagulant to the mixed treated water to react to pH 9 to 10 to flocculate it. To provide a wastewater treatment method using mixed treatment of dyeing wastewater and wastewater from other industries, which can most efficiently and quickly remove non-degradable contaminants contained in dyeing wastewater by precipitation.

To solve the above problem, a wastewater treatment method using mixed treatment of dyeing wastewater and wastewater from a different industry according to an embodiment of the present invention includes the steps of (a) injecting Ca(OH) ₂ and FeSO ₄ into the wastewater from a different industry and reacting it; (b) mixing and stirring the dyeing wastewater homogenized with the reacted wastewater from a different industry in a neutralization tank, then injecting FeSO ₄ and Ca(OH) ₂ to react to pH 9 to 10; (c) adding a coagulant to the mixed treated water reacted at pH 9 to 10 to cause coagulation and precipitation; (d) neutralizing the coagulated and precipitated mixed water to pH 6 to 8 by injecting sulfuric acid (H ₂ SO ₄ ); and (e) introducing the neutralized mixed treatment water into an aeration tank, decomposing organic matter through biological treatment, and then precipitating it and discharging the supernatant.

The step (a) includes (a-1) introducing wastewater from a different industry into the reaction tank through a pipe dedicated to wastewater from a different industry and a collection tank for wastewater from a different industry; (a-2) adjusting the pH to 11 to 12 by injecting Ca(OH) ₂ into the wastewater from other industries flowing into the reaction tank; And (a-3) injecting FeSO ₄ into the industrial wastewater adjusted to pH 11 to 12 and reacting at pH 3 to 5.

In step (b), the homogenized dyeing wastewater is removed by precipitating the sand component of the dyeing wastewater flowing in through a dedicated wastewater pipe using a silt tank, and the waste mixed in the dyeing wastewater is filtered through a screen tank. The dyeing wastewater that has been separated and removed and passed through the screen tank is mixed homogeneously in an equalization tank and a flow rate adjustment tank to maintain the inflow load at the set value.

The coagulant is preferably a polymer.

The step (c) includes (c-1) introducing the mixed treated water reacted to pH 9 to 10 into a flocculation tank and flocculating it by adding a coagulant; and (c-2) flowing the mixed treated water flocculated by the coagulant into a primary sedimentation tank and allowing it to gravity settle to separate it into a supernatant and sludge.

In step (c-2), the supernatant separated by gravity settling in the primary sedimentation tank is introduced into the primary treatment tank to be neutralized with sulfuric acid (H ₂ SO ₄ ), and the sludge is stored in the primary sludge storage tank.

The step (e) includes (e-1) introducing the neutralized mixed treatment water into an aeration tank, decomposing organic matter through biological treatment, and then separating it into a supernatant and sludge by gravity settling it in a secondary sedimentation tank; and (e-2) flowing the supernatant separated by gravity sedimentation in the secondary sedimentation tank into the discharge tank, measuring the flow rate of the supernatant with a flow meter, adjusting the pH, and discharging it to the terminal treatment plant.

In step (e-1), the supernatant separated by gravity settling in the secondary sedimentation tank is re-introduced into the flow control tank through the drain pipe.

In step (e-1), the supernatant separated by gravity settling in the secondary sedimentation tank is introduced into a discharge tank and discharged to a terminal treatment plant, and the sludge is stored in a secondary sludge storage tank.

The sludge stored in the primary and secondary sludge storage tanks is transferred to a mixing tank, dehydrated, and discharged after cake treatment through a cake storage facility.

The wastewater treatment method using the mixed treatment of dyeing wastewater and wastewater from a different industry according to the present invention involves mixing homogenized dyeing wastewater with wastewater from a different industry in a neutralization tank, stirring the mixture, and then injecting FeSO ₄ and Ca(OH) ₂ to pH 9. By adding a coagulant to the mixed treated water reacted at ~10 to cause coagulation and precipitation, it is possible to most efficiently and quickly remove non-degradable contaminants contained in dyeing wastewater.

In addition, the wastewater treatment method using mixed treatment of dyeing wastewater and wastewater from other industries according to the present invention involves gravity settling in a secondary sedimentation tank and re-introducing the separated supernatant into the neutralization tank through a drain pipe, thereby removing non-decomposable contaminants in the sediment. The Fe ²⁺ component reacting with is dissolved in sulfuric acid and then combined with sulfuric acid to be regenerated into an iron salt solution and reused, thereby reducing the cost of using FeSO ₄ .

As a result, the wastewater treatment method using the mixed treatment of dyeing wastewater and wastewater from other industries according to the present invention can minimize the amount of sludge generated by reducing the input amount of sulfuric acid, hydrogen peroxide, and caustic soda and reducing the overall chemical usage through recycling of FeSO ₄ . Therefore, it becomes possible to secure economic feasibility by reducing wastewater treatment costs.

Figure 1 is a process flow chart showing a wastewater treatment method using mixed treatment of dyeing wastewater and wastewater from different industries according to an embodiment of the present invention.
Figure 2 is a process schematic diagram showing a wastewater treatment method using mixed treatment of dyeing wastewater and wastewater from different industries according to an embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in more detail with reference to the attached drawings. However, the present invention is not limited to the embodiments disclosed below and will be implemented in various different forms. These embodiments only serve to ensure that the disclosure of the present invention is complete and to those skilled in the art to fully convey the scope of the invention. This is provided to inform you. In the drawings, like symbols refer to like elements.

It is intended to be clear that the division of components in this specification is merely a division according to the main function each component is responsible for. That is, two or more components, which will be described below, may be combined into one component, or one component may be divided into two or more components for more detailed functions. In addition to the main functions it is responsible for, each of the components described below may additionally perform some or all of the functions handled by other components, and some of the main functions handled by each component may be performed by other components. Of course, it can also be carried out exclusively by . Therefore, the presence or absence of each component described throughout this specification should be interpreted functionally.

Hereinafter, the characteristics of the wastewater treatment method using the mixed treatment of dyeing wastewater and wastewater from other industries according to the present invention will be described in detail with reference to the attached drawings.

Figure 1 is a process flow chart showing a wastewater treatment method using mixed treatment of dyeing wastewater and wastewater from a different industry according to an embodiment of the present invention, and Figure 2 is a process flow chart showing a mixed treatment of dyeing wastewater and wastewater from a different industry according to an embodiment of the present invention. This is a process schematic diagram showing the wastewater treatment method used.

Referring to Figures 1 and 2, the wastewater treatment method using mixed treatment of dyeing wastewater and other industry wastewater according to an embodiment of the present invention includes a second industry wastewater treatment step (S110), a second industry wastewater and dyeing wastewater mixing treatment step ( S120), flocculation and precipitation treatment step (S130), neutralization treatment step (S140), and biological treatment step (S150).

Wastewater treatment for different industries

In the second-industry wastewater treatment step (S110), Ca(OH) ₂ and FeSO ₄ are injected into the second-industry wastewater to react.

This second-industry wastewater treatment step (S110) is a process of introducing the second-industry wastewater into the reaction tank 114 through the second-industry wastewater exclusive pipe 110 and the second-industry wastewater collection tank 112, and the process of introducing the second-industry wastewater into the reaction tank 114. It includes the process of injecting Ca(OH) ₂ into industrial wastewater to adjust pH to 11 to 12, and the process of injecting FeSO ₄ into industrial wastewater adjusted to pH 11 to 12 and reacting at pH 3 to 5.

Mixed treatment of wastewater from different industries and dyeing wastewater

In the mixing treatment step (S120) of wastewater from a different industry and dyeing wastewater, the homogenized dyeing wastewater and the reacted wastewater from a different industry are mixed and stirred in a neutralization tank (120), and then FeSO ₄ and Ca(OH) ₂ are injected to adjust the pH. React with steps 9 to 10.

As such, in the present invention, FeSO ₄ and Ca(OH) ₂ were used to most efficiently and quickly remove non-decomposable contaminants contained in wastewater from other industries and dyeing wastewater. Taking advantage of the fact that FeSO ₄ has a high reaction efficiency not only under strong acidic conditions but also under strong alkaline conditions, Ca(OH) ₂ is added to the wastewater from other industries and dyeing wastewater to create a strong alkaline state, and then the non-decomposable wastewater contained in the wastewater from other industries and dyeing wastewater is created. A method of reacting contaminants with FeSO ₄ and removing them by gravity sedimentation was used.

In other words, when Ca(OH) ₂ is added to the wastewater of other industries and dyeing wastewater to create a strong alkaline state, and then the non-decomposable contaminants contained in the wastewater of other industries and dyeing wastewater are reacted with FeSO ₄ , Fe ² in FeSO ₄ After the ⁺ component is separated from the SO ₄ ^2- group due to the strong alkaline reducing atmosphere, it quickly combines with non-decomposable contaminants in wastewater from other industries and dyeing wastewater, forming flocs and causing the particles to become larger. Accordingly, coagulation and sedimentation occur quickly in the subsequent coagulation and sedimentation treatment step (S130), making it possible to easily control sediment containing non-decomposable contaminants.

Accordingly, in the present invention, unlike the conventional Fenton oxidation method, a large amount of sulfuric acid or hydrochloric acid is added to alkaline dyeing wastewater to adjust the pH of 3 to 3.5, which is the Fenton oxidation condition, and to generate OH ^- radical groups for color treatment. Since there is no need to add hydrogen peroxide, the amount of chemical used can be significantly reduced.

Here, the homogenized dyeing wastewater is removed by precipitating the sand component of the dyeing wastewater flowing in through the dedicated wastewater pipe 130 using the silt tank 132, and the waste mixed in the dyeing wastewater and flowing in is filtered into the screen tank 134. The dyeing wastewater that has passed through the screen tank 134 is separated and mixed homogeneously in the equalization tank 136 and the flow rate adjustment tank 138 to maintain the inflow load at the set value.

In this way, since the dyeing wastewater flowing in through the dedicated wastewater pipe 130 is heterogeneous dyeing wastewater, the sand component is precipitated and removed using the silt tank 132, and then the heterogeneous dyeing wastewater is removed through the screen tank 134. Coarse waste mixed in dyeing wastewater is separated and removed.

Thereafter, a certain amount of the heterogeneous dyeing wastewater that has passed through the screen tank 134 is sequentially introduced into the equalization tank 136 and the flow rate adjustment tank 138 using the flow meter 135. At this time, since the properties of the dyeing wastewater flowing into the equalizing tank 136 and the flow adjusting tank 138 are different at each time, the inflow load is kept constant by homogeneously mixing the heterogeneous dyeing wastewater flowing in.

In particular, in this step (S120), the wastewater from different industries and the homogenized dyeing wastewater are mixed and stirred in the neutralization tank 120, and then FeSO ₄ and Ca(OH) ₂ are injected to react to pH 9 to 10.

At this time, stirring is preferably performed for 10 to 120 minutes at a speed of 1,500 to 3,000 rpm. If the stirring speed is less than 1,500 rpm or the stirring time is less than 10 minutes, FeSO ₄ and Ca(OH) ₂ may not be mixed homogeneously in the wastewater from other industries and the homogenized dyeing wastewater, which may lead to difficulties in adjusting pH. If it exceeds 3,000 rpm or the stirring time exceeds 120 minutes, it may act as a factor that only increases manufacturing costs without any further effect, making it uneconomical.

In addition, when stirring, it is more desirable to perform ultrasonic treatment at a frequency of 25 to 45 KHz and an output voltage of 10 to 20 W, to maximize the combination of non-degradable contaminants in the wastewater from different industries and the homogenized dyeing wastewater. It is for this purpose. When applying ultrasonic waves, if the frequency is less than 25 KHz or the output voltage is less than 10 W, the cavitation effect caused by the application of ultrasonic waves is minimal, making it difficult to properly demonstrate the effect of applying ultrasonic waves. If the frequency of ultrasonic waves exceeds 45 KHz, or the output voltage is If it exceeds 20W, it is not desirable because there is a risk of poor economic efficiency due to excessive application of ultrasonic waves without further increase in effectiveness.

Flocculation and sedimentation treatment

In the coagulation and precipitation treatment step (S130), a coagulant is added to the mixed treatment water reacted to pH 9 to 10 to cause coagulation and precipitation. Here, it is preferable to use a polymer as a coagulant.

This coagulation and sedimentation treatment step (S130) is a process of introducing mixed treated water reacted to pH 9 to 10 into the flocculation tank 140, flocculating it by adding a coagulant, and mixing the mixed treated water flocculated by the coagulant into 1 It includes the process of flowing into the secondary settling tank 142 and separating it into supernatant and sludge by gravity settling.

At this time, the supernatant separated by gravity settling in the primary sedimentation tank 142 is introduced into the primary treatment tank 146 to be neutralized with sulfuric acid (H ₂ SO ₄ ), and the sludge is stored in the primary sludge storage tank 144. Here, the primary treatment water tank 146 is cooled to a constant temperature by the cooling tower 148.

neutralization treatment

In the neutralization treatment step (S140), sulfuric acid (H ₂ SO ₄ ) is injected into the coagulated and precipitated mixed treatment water to neutralize it to pH 6 to 8.

In this way, when sulfuric acid (H ₂ SO ₄ ) is injected into the coagulated and precipitated mixed treatment water to neutralize it to pH 6 to 8, the Fe ²⁺ component reacting with the non-decomposable contaminants in the sediment is dissolved in sulfuric acid. After combining with sulfuric acid, it can be regenerated into an iron salt solution and reused, thereby reducing the cost of using FeSO ₄ .

biological treatment

In the biological treatment step (S150), the neutralized mixed treatment water is introduced into the aeration tank 150 to decompose organic matter through biological treatment, and then precipitated and the supernatant is discharged.

In this way, the mixed treatment water, which has been neutralized to pH 6 to 8 by injecting sulfuric acid (H ₂ SO ₄ ), stays in the aeration tank 150 for a long time and is neutralized as the activity of aerobic microorganisms becomes active due to aerobic conditions caused by air. Organic matter in the treated mixed water is decomposed by microorganisms.

In this biological treatment step (S150), the neutralized mixed treatment water is introduced into the aeration tank 150 to decompose organic matter through biological treatment, and then separated into supernatant and sludge by gravity settling in the secondary sedimentation tank 152. , It includes the process of flowing the supernatant separated by gravity sedimentation in the secondary sedimentation tank 152 into the discharge tank 156, measuring the flow rate of the supernatant with the flow meter 155, adjusting the pH, and discharging it to the terminal treatment plant. .

In addition, the supernatant separated by gravity settling in the secondary settling tank 152 is re-introduced into the flow adjustment tank 138 through the drain pipe 158. Accordingly, in the flow adjustment tank 138, wastewater generated during the wastewater treatment process is re-introduced and mixed together with wastewater from other industries and homogenized dyeing wastewater through the drain pipe 158, and the flow rate load is adjusted through the flow adjustment tank 138. remains constant.

As such, in the present invention, the supernatant separated by gravity sedimentation in the secondary sedimentation tank 152 is re-introduced into the flow rate adjustment tank 138 through the drain pipe, thereby removing the Fe ²⁺ component that was reacting with the non-decomposable contaminants in the sediment. After being dissolved in sulfuric acid, it combines with sulfuric acid and is regenerated into an iron salt solution so that it can be reused, thereby reducing the cost of using FeSO ₄ .

Therefore, unlike the prior art, the present invention can minimize the amount of sludge generated by reducing the input amount of sulfuric acid, hydrogen peroxide, and caustic soda and reducing the overall chemical usage through recycling of FeSO ₄ , making it possible to secure economic feasibility by reducing wastewater treatment costs. It becomes possible.

In addition, the supernatant separated by gravity settling in the secondary sedimentation tank 152 flows into the discharge tank 156 and is discharged to the terminal treatment plant, and the sludge is stored in the secondary sludge storage tank 154. In this way, the discharge tank 156 measures the flow rate of the supernatant separated from solid and liquid in the secondary sedimentation tank 152 using the flow meter 155, adjusts the pH, and discharges it to the terminal treatment plant.

Here, the sludge stored in the primary and secondary sludge storage tanks 144 and 154 is transferred to the mixing tank 160, then dehydrated through the dehydration facility 162 and cake treated through the cake storage facility 164. It is released.

As explained so far, the wastewater treatment method using a mixed treatment of dyeing wastewater and wastewater from a different industry according to an embodiment of the present invention mixes dyeing wastewater homogenized with wastewater from a different industry in a neutralization tank, stirs it, and then mixes FeSO ₄ and Ca By injecting (OH) ₂ and adding a coagulant to the mixed treatment water, which has reacted to pH 9 to 10, to coagulate and precipitate, non-decomposable contaminants contained in dyeing wastewater can be removed most efficiently and quickly.

In addition, the wastewater treatment method using mixed treatment of dyeing wastewater and wastewater from other industries according to an embodiment of the present invention re-introduces the supernatant separated by gravity sedimentation in the secondary sedimentation tank into the neutralization tank through the drain pipe, thereby removing the eggs in the sediment. The Fe ²⁺ component reacting with decomposable pollutants is dissolved in sulfuric acid and then combined with sulfuric acid to be regenerated into an iron salt solution and reused, thereby reducing the cost of using FeSO ₄ .

As a result, the wastewater treatment method using mixed treatment of dyeing wastewater and wastewater from other industries according to the embodiment of the present invention reduces the input amount of sulfuric acid, hydrogen peroxide, and caustic soda, and reduces the overall chemical usage through recycling of FeSO ₄ , thereby reducing the amount of sludge generated. Because it can be minimized, it becomes possible to secure economic feasibility by reducing wastewater treatment costs.

Although the embodiments of the present invention have been described in detail as described above, the scope of the rights of the present invention is not limited thereto, and the scope of the rights of the present invention extends to the scope substantially equivalent to the embodiments of the present invention.

S110: Industrial wastewater treatment step
S120: Mixing treatment step of wastewater from other industries and dyeing wastewater
S130: Coagulation and precipitation treatment step S140: Neutralization treatment step
S150: Biological treatment step 110: Pipe dedicated to wastewater from other industries
112: Industrial wastewater collection tank 114: Reaction tank
120: Neutralization tank 130: Exclusive wastewater pipe
132: Silt tank 134: Screen tank
136: equalization tank 138: flow adjustment tank
140: flocculation tank 142: primary sedimentation tank
144: primary sludge storage tank 146: primary treatment tank
148: cooling tower 150: aeration tank
152: secondary sedimentation tank 154: sludge storage tank
156: Discharge tank 158: Drain piping
160: mixing tank 162: dehydration facility
164: Cake storage facility

Claims (10)

(a) reacting by injecting Ca(OH) ₂ and FeSO ₄ into wastewater from other industries;
(b) mixing and stirring the dyeing wastewater homogenized with the reacted wastewater from a different industry in a neutralization tank, then injecting FeSO ₄ and Ca(OH) ₂ to react to pH 9 to 10;
(c) adding a coagulant to the mixed treated water reacted to pH 9 to 10 to cause coagulation and precipitation;
(d) neutralizing the coagulated and precipitated mixed water to pH 6 to 8 by injecting sulfuric acid (H ₂ SO ₄ ); and
(e) introducing the neutralized mixed treatment water into an aeration tank to decompose organic matter through biological treatment, then precipitating it and discharging the supernatant;
In step (a), the industrial wastewater is domestic wastewater,
The step (a) includes (a-1) introducing wastewater from a different industry into the reaction tank through a pipe dedicated to wastewater from a different industry and a collection tank for wastewater from a different industry; (a-2) adjusting the pH to 11 to 12 by injecting Ca(OH) ₂ into the wastewater from other industries flowing into the reaction tank; and (a-3) injecting FeSO ₄ into the wastewater from a different industry adjusted to pH 11 to 12 and reacting it at pH 3 to 5. Using mixed treatment of dyeing wastewater and wastewater from a different industry, comprising: Wastewater treatment method. delete According to paragraph 1,
In step (b) above,
The homogenized dyeing wastewater is
The sand component of the dyeing wastewater flowing in through the dedicated wastewater pipe is removed by precipitating it using a silt tank.
Waste mixed in the dyeing wastewater is separated and removed through a screen tank,
A wastewater treatment method using mixed treatment of dyeing wastewater and wastewater from other industries, characterized in that the dyeing wastewater that has passed through the screen tank is mixed homogeneously in an equalization tank and a flow rate adjustment tank to maintain the inflow load at a set value. According to paragraph 1,
The coagulant is
A wastewater treatment method using mixed treatment of dyeing wastewater and wastewater from other industries, which is characterized as being polymer. According to paragraph 1,
In step (c),
(c-1) introducing the mixed treated water reacted to pH 9 to 10 into a flocculation tank and flocculating it by adding a coagulant; and
(c-2) A wastewater treatment method using mixed treatment of dyeing wastewater and wastewater from other industries, characterized in that the mixed treated water coagulated by the coagulant is introduced into the primary sedimentation tank and subjected to gravity sedimentation to separate it into supernatant and sludge. According to clause 5,
In step (c-2),
The supernatant separated by gravity settling in the primary sedimentation tank is introduced into the primary treatment tank and neutralized with sulfuric acid (H ₂ SO ₄ ), and the sludge is stored in the primary sludge storage tank. Dyeing wastewater and wastewater from other industries Wastewater treatment method using mixed treatment. According to paragraph 1,
In step (e),
(e-1) introducing the neutralized mixed treatment water into an aeration tank to decompose organic matter through biological treatment, and then separating it into a supernatant and sludge by gravity settling it in a secondary sedimentation tank; and
(e-2) flowing the supernatant separated by gravity sedimentation in the secondary sedimentation tank into the discharge tank, measuring the flow rate of the supernatant with a flow meter, adjusting the pH, and discharging it to the terminal treatment plant;
A wastewater treatment method using mixed treatment of dyeing wastewater and wastewater from other industries, comprising: In clause 7,
In step (e-1) above,
A wastewater treatment method using mixed treatment of dyeing wastewater and wastewater from other industries, characterized in that the supernatant separated by gravity settling in the secondary sedimentation tank is re-introduced into the flow rate adjustment tank through a drain pipe. In clause 7,
In the step (e-1), the supernatant separated by gravity settling in the secondary sedimentation tank is introduced into a discharge tank and discharged to a terminal treatment plant, and the sludge is stored in a secondary sludge storage tank. Wastewater treatment method using wastewater mixing treatment. According to clause 6 or 9,
Sludge stored in the primary or secondary sludge storage tank is
A wastewater treatment method using mixed treatment of dyeing wastewater and wastewater from other industries, characterized in that each is transferred to a mixing tank, dehydrated, and discharged after cake treatment through a cake storage facility.